Question: 6 rubber stamps cost $8.04. Which equation would help determine the cost of 7 rubber stamps?
Explanation: There are several equations that could help determine the cost, each with a slightly different approach. If we let $x$ represent the cost of 7 rubber stamps, we have the following proportion: $\dfrac{x}{7}$ We have to pay $8.04 for 6 rubber stamps, and that can be written as a proportion: $\dfrac{\$8.04}{6}$ Since the price per rubber stamp stays the same, these two proportions are equivalent. $\dfrac{x}{7} = \dfrac{\$8.04}{6}$